#include #include int main() { int x1, y1, x2, y2, x3, y3; double a, b, c, s, area; scanf("%d%d%d%d%d%d", &x1, &y1, &x2, &y2, &x3, &y3); a = sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)); b = sqrt((x1 - x3) * (x1 - x3) + (y1 - y3) * (y1 - y3)); c = sqrt((x2 - x3) * (x2 - x3) + (y2 - y3) * (y2 - y3)); if (a + b > c && a + c > b && b + c > a) { s = (a + b + c) / 2; area = sqrt(s * (s - a) * (s - b) * (s - c)); printf("%.1f %.1f\n", a + b + c, area); } else { printf("no triangle!\n"); } return 0; }